Q-jet vacuum/electrical questions.

[flyboy1100]

pretty sure this thing is original, no idea if it has ever been rebuilt, but at some point pretty much all vacuum lines were removed and capped. most things are INOP currently, such as the air door in the intake. I would like to get some of it back, all of the emissions were also disconnected. I'm not looking to get it back to stock, but it would be nice if the following were working correctly.
1. vac advance
2. cruise control
3. air flapper in intake (it gets cold here in the winter)
3. anything else absolutely required

also there are a few electrical connectors it looks like that have been disconnected. are they needed? would the carb operate better with them?

 

[flyboy1100]

I should add I have the vacuum diagram, but what do the letters stand for?

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[chengny]

Wow - that is a mess. Emissions code YDP?

You have a few options:

1. Attempt to return all components to working condition

2. Identify only what you feel you need/want to have operational. Fix only those components and eliminate the rest.

3. Strip it all away and only run the necessities



The first option will be time consuming and possibly expensive.

The second option will be easier but everything that remains may not work as designed.

The third option might be your best bet. I used to struggle to maintain the full factory controls but it just got too expensive and I really did not see any increased performance.

My SBC's now have the following:

5 wires. They go to;

1. The oil pressure switch (with a lead to operate the choke heater)
2. The oil pressure sender (for dash indication)
3. The coolant temperature sensor (as above)
4. The alternator (2) wires. Power and excitation

The EGR valve is a dummy (blocked with a sheet metal blank between the flanges)

I run the distributor's vacuum advance to an unported source (e.g the F tap down low in the back of the carb - next to the vacuum line for the brake booster ). Some folks like to use a ported tap point. I have not noticed any difference one way or another. These are trucks not race cars.

If the air pumps are still capable of blowing air ( and the injection system is intact) I remove the vacuum lines and the leads to the diverter valves. This lets them run all the time and keep the exhaust cool.

The carburetors have no controls (other than the aforementioned choke heater). You appear to have a carb that is set up for ECM control of the mixture control solenoid. With it unhooked - as it is now - you are running on the default mixture (i.e. heavy). Either get a carb without an MCS or - if your ECM is still functional - hook the wire back up.

Description and Operation


Fuel flow through the carburetor idle/main circuit is controlled by MC solenoid controlled metering rods. The MC solenoid controls air/fuel mixtures by allowing more or less fuel to flow through the carburetor. The ECM controls MC solenoid operation by completing or breaking the solenoid ground circuit.
When the MC solenoid is energized (down position), fuel flow is reduced, providing leaner mixtures. When the solenoid circuit is open (up position), more fuel is allowed to flow, providing richer mixtures. The ECM cycles the MC solenoid ``on and off'' at a fixed rate of 10 times per second, but varies the amount of time that the solenoid is energized per cycle (dwell period) to control air/fuel mixture.

Forget the Thermac system - they are great when they work but often they dont (work).

If you are having hard warm-ups in the winter just adjust the choke heater to stay closed a bit longer. NH is not as cold as ND but it ain't tropical either and I warm up fine - even on the coldest winter mornings.

That cylinder with a plunger on the LH side is an Idle Speed Control. Again it is ECM driven. If it doesn't operate now - and you are idling okay - lose it.

Description and Operation


The ISC assembly controls engine idle speed according to ECM programming.

When the throttle lever rests against the ISC plunger, the ISC acts as a dashpot on throttle closing per second.

Buy some flush fit stainless steel plugs, pull all the TVS's and plug the tapped holes.

I don't know if this is what you were looking for, but it may be of some help.

 

[flyboy1100]

1. where would the computer be if I had one? it is a 1986 truck.
2. I'm pretty sure I only want to do option 3. all the emissions except EGR are gone. Air pump and piping is long gone, manifolds were plugged. (planning headers anyway)
3. pretty sure choke isn't working, never have need the flapper/plate thing move on a cold start, albeit never colder than 60F currently.
4. LH side, behind the choke? i just want to make sure we are on the same page.

I do have the vac diagram under the hood, not sure of Emissions code currently, but YDP sounds correct. there are letter labels on the carb that various lines connect too, what do they stand for?

 

[chengny]

1. Under the dash above the glove box:

You must be registered for see images attach

4. The Idle Speed Control is in front of the throttle linkage:

You must be registered for see images attach

there are letter labels on the carb that various lines connect too, what do they stand for?

They're arbitrary markings - at least I don't think they stand for anything. They vary from carb to carb.
Where they lead to - once inside the carb - is a heavily guarded secret, known only to a handful of people. Most of whom are now dead.

Seriously, I think they were labeled that way at the request of the auto manufacturers to facilitate vacuum tubing connections. Probably, -if Rochester had it's way, there would be no markings.

There are a couple of tricky ones but a good rule of thumb is: if the port is way down low (below the throttle plates) it is full vacuum. The ones higher up are timed ports that see vacuum only when the throttle is opened.

Watch this - it's pretty informative:

https://www.youtube.com/watch?v=6qaSCe0QDe4

 

[flyboy1100]

computer is still there, but nothing at all is hooked up on the engine. maybe if i get motivated enough I will remove it, i'm sure everything that is engine side is shot.

my mixture screws don't seem to work, primarily because the computer should be controlling it?

thanks for the video, very informative

 

[chengny]

my mixture screws don't seem to work, primarily because the computer should be controlling it?

Yeah - exactly. Like it says up above in this thread somewhere, if the mixture control solenoid is non-functional (for whatever reason), both the idle and main circuits default to rich the setting.

I have no idea how this happens - or whether you can override the default by adjusting the mixture screws. But, trust me on this, installing an MCS equipped carburetor in a non-computer controlled truck does not work well at all.

I once bought a brand new (still in the box) Rochester Quadrajet from a guy for $100. It was a Craigslist deal - the exchange was done in a highway rest area at night. I didn't notice the little blue (or green - I'm color blind) solenoid cap until I got home. Even then I thought it was a great deal. A brand new Q-jet for $100 - WOW.

Problem was, I had a 86 K20 with a federal heavy duty emissions package. No computer, no cats, no O2 sensors, nothing. Long story short; the truck ran like crap with the MCS carb. Put my old non-MCS Q-jet back on and it ran fine. Couldn't find anyone who needed the MCS version. Couldn't sell it - and so I ended up giving it away.

Point of that long story is - if your ECU is non-functional and you can find a decent Roch Q-jet (without the MCS) get it and install it. Your truck may run way better than it does now.

 

[flyboy1100]

I need to figure out what years that is, I know there are 2 84s in the junk yard I'm getting other things from.

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[chengny]

Figure out what years what is?

You know, if you're up for it - and the junkyards in your area have plenty of these trucks - you could probably pull all the components required to restore most of the emissions package.

By far, the most expensive components are the one's associated with the air injection system - and that's if you can even find them. So, since that part of the emissions package is not a factor, restoring the remainder would not be all that hard.

There is a really good chance that your ECU is still fully operational - those early engine control systems were fairly basic and the modules were simple. Other than a tendency to develop cracks in the solder joints of the PC board, they were dependable.

It can seem confusing but, keep in mind that the engine control and emissions packages are independent of each other and are operated by different means:

The engine control system is primarily electrical. It is a group of:

1. Sensors, actuators and electronics on the engine.
2. The ECU under the dash.
3. The wiring that links everything together.

On the other hand, the emissions control system is almost totally vacuum operated. The only electrically controlled components in the emissions system - that I can think of - are the air pump diverter valve solenoids and a vapor canister purge solenoid. The operation of everything else is by vacuum and these components are controlled by either the various TVS's or the ported connections on the carburetor.

Here is a picture showing the location of the most common engine components that were used on the 1986 C/K series:

You must be registered for see images attach

Your engine code is going to be an "L" . This can be confirmed by checking the 8th digit of your VIN.

There are two types of "L" engine codes Federal & California. Assuming you have a Federal package, the following devices were originally installed:

Engine V8-350
Application 4 Bbl. Exc. Calif.
Engine Code [1] L
Figure No. 119
Devices & Systems
AIR, BPEGR, CC, DEC-V, DV, DVDV, EEC, EFE, EFE/DS-TVS, EGR-BS, EGR-SOL, ESC, ESC-KS, OC, PCV, TAC, TCC



The component key:

EXPLANATION OF SYSTEMS AND DEVICES



ABA Air Bleed Actuator
ACC Auxiliary Charcoal Canister
ACS Air Control Valve
AIR Air Injection Reaction
AIR-DS Air Injection Reaction Divert Solenoid
AIR-MGMT Air Injection Reaction Management System
AIR-SVV Air Injection Reaction Switching Solenoid Valve
APS Absolute Pressure Sensor
ASV Absolute Pressure Sensor
A.T. Automatic Transmission
BARO Barometric Pressure Sensor
BPEGR Back Pressure Exhaust Gas Recirculation
BPS Barometric Pressure Sensor
BPT Back Pressure Transducer
BVV Bowl Vent Valve
CAC Cold Advance Control
CC Charcoal Canister
CCV Canister Control Vent
CDR Crankcase Depression Regulator
CLFC Closed Loop Fuel Control
CP-TVS Canister Purge Thermal Vacuum Switch
CP-SOL Canister Purge Solenoid
CTS Coolant Temperature Sensor
C3 Computer Command Control
CV Crankcase Ventilation
DC Deceleration Control
DEC Diesel Electronic Control System
DEC-MCV Deceleration Mixture Control Valve
DEC-V Deceleration Valve
DPS Differential Pressure Sensor
DC/CP-TVS Distributor Spark & Canister Purge ThermalVacuum Switch
DS-DV Distributor Spark Delay Valve
DS/EGR-TVS Distributor Spark & Exhaust Gas Recirculation Thermal Vacuum Switch
DS/P-TVS Distributor Purge Thermal Vacuum Switch
DS/TCC-TVS Distributor Spark & Tramsmission ConverterClutch Thermal VacuumSwitch
DS-TVS Distributor Purge Thermal Vacuum Switch
DS-VCV Distributor Spark Vacuum Check Valve
DS-VR Distributor Spark Vacuum Regulator
DTVS Distributor Thermal Vacuum Switch
DV Diverter Valve
DVDV Distributor Vacuum Delay Valve
DVR-SOL Diverter Solenoid
EAC Electric Air Control Solenoid
EAC-V Electric Air Control Valve
EAC/EAS-V Electric Air Control & Electric Air Switching(Integral Type)
ED/ES-V Electric Diverter/Electric Air Switching Valve
EDV Electric Diverter Valve
EEC Evaporative Emission Control
EEC-PV Evaporative Emission Control Purge Valve
EEC-S Evaporative Emission Control Sensor
EEC-TVS Evaporative Emission Control Thermal Vacuum Switch
EFE Early Fuel Evaporation System
EFE/DS-TVS Early Fuel Evaporation & Diustributor Spark ThermalVacuum Switch
EFE-SOL Early Fuel Evaporation Solenoid
EFE/EGR-SOL Early Fuel Evaporation/Exhaust Gas Recirculation Solenoid
EFE-TVS Early Fuel Evaporation Thermal Vacuum Switch
EFE-VCV Early F uel Evaporation Vacuum Check Valve
EGR Exhaust Gas Recirculation
EGR-BPT Exhaust Gas Recirculation Back Pressure Transducer
EGR-BS Exhaust Gas Recircualtion Bleed Solenoid
EGR/CP-TVS Exhaust Gas Recircualtion & Canister Purge Thermal vacuum Switch
EGR/CP/DS-TVS Exhaust Gas Recirculation, Canister Purge &Distributor Spark Thermal Vacuum Switch
EGR/CP/TS-TVS Exhaust Gas Recirculation, Canister Purge &Trapped Spark Thermal Vacuum Switch
EGR/CP/TCC-TVS Exhaust Gas Recircualtion, Canister Purge &Torque Converter Clutch Thermal Switch
EGR/PWM-SOL Pulse Width Modulated Exhaust Gas Recirculation
EGR-S Exhaust Gas Recirculation Sensor
EGR-SOL Exhaust Gas Recirculation Solenoid
EGR-TDS Exhaust Gas Recirculaiton Temperature Diagnosis Switch
EGR-TVS Exhaust Recircualtion Thermal Vacuum Switch
EGR/TCC-TVS Exhaust Gas Recircualtion & Torque Converter ClutchThermal Vacuum Switch
EGR-VBS Exhaust Gas Circulation Vacuum Bleed Solenoid
EGR-VDS Exhaust Gas Recirculation Vacuum Diagnosis Switch
EGR-VRV Exhaust Gas Recircualtion Vacuum Regulator Valve
EGR-VS Exhaust Gas Recircualtion Vacuum Switch
EGR-VSV Exhaust Gas Recircualtion Vacuum Switching Valve
EPR Exhaust Pressure Regulator
EPR-SOL-EPR Solenoid
EPR Electric Purge Solenoid
EPR-SOL-EPR Solenoid
EPS Electric Purge Solenoid
ESC Electronic Spark Control System
ESC-KS Electronic Spark Control Knock Sensor
ESR Engine Speed Relay
ESS Engine Speed Sensor
EST Electronic Spark Timing
ETK Electronic Throttle Kicker
ETM Elapsed Timer Module
EVRV Electronic Vacuum Regulator Valve
FCS Fuel Control System
FIS Fast Idle Solenoid
FM Fuel Module
FVV Fuel Vapor Valve
HDE Heavy Duty Emission Calibration
HIC Hot Idle Compensator
IAC Idle Air Control
ISC Idle Speed control Motor
ISS Idle Stop Solenoid
LALS Lean Authority Limit Switch
LDE Light Duty Emission Calibration
MAIR Managed Air Injection Reaction
MAP Manifold Absolute Pressure Sensor
MAT Manifold Air Temperature Sensor
MCS Mixture Control System
MDE Medium Duty Emission Calibration
MDPS Manifold Depression Pressure Sensor
M.T. Manual Transmission
OC Oxidizing Catalyst
ORC Oxidation Reduction (3-Way) Catalyst
ORC/OC Oxidation Reduction & Oxidizing (3-Way &dual bed) Catalyst
OS Oxygen Sensor
PCS Purge Control Solenoid
PCV Positive Crankcase Ventilation
PWM-EGR Pulse Width Modulated Exhaust Gas Recirculation
P-TVS Purge Thermal Vacuum Switch
RVR Response Vacuum Reducer
SCS Slow Idle Fuel Cut Solenoid
SRDV Spark Retard Delay Valve
SSCS Stepped Speed Control Solenoid
SVB-TVS Secondary Vacuum Break Thermal Vacuum Switch
SVB/EGR-TVS Secondary Vacuum Break Exhaust GasRecirculation Thermal Vacuum Switch
TAC Thermostatic Air Cleaner
TBI Throttle Body Injection
TCC Tranwmission Torque Converter
TCC/EGR/CP/TS-VS Torque Converter Clutch, EGR, Canister Purge& Trapped Spark Thermal Switch
TCC-TVS Transmission Converter Clutch Thermal Vacuum Switch
TCC-VDV Transmission Converter Clutch Vacuum Delay Valve
TIVS Tip-In Vacuum Switch
TK Throttle Kicker
TPS Throttle Position Sensor
TRC Throttle Return Control
TVR Throttle Valve Relay
TVS Thermal Vacuum Switch
TVSS Trapped Vacuum Spark System
TVV Thermal Vacuum Valve
VB-TVS Vacuum Break Thermal Vacuum Switch
VCV Vacuum Control Valve
VDV Vacuum Delay Valve
VMV Vacuum Modulator Valve
VR Vacuum Regulator
VRV Vacuum Regulator Valve
VS Vacuum Sensor
VSS Vehicle Speed Sensor
VSV Vacuum Switching Valve

If you go through the list of what was on your truck (and eliminate all the emissions stuff) you have only about 5 components.

I don't know why that ISC actuator is not listed - it isnot on the Calif list either.

 

[MadOgre]

There are a couple of tricky ones but a good rule of thumb is: if the port is way down low (below the throttle plates) it is full vacuum. The ones higher up are timed ports that see vacuum only when the throttle is opened.

This is not true on Rochester carburetors.

Your on the right track looking for a different carb with out the electronics.

Just go to the junk yard, and look for one that has electric choke with no electrical connections. You can always rejet if necessary.

The key is to find one that has the butterfly shafts in good shape, no slop and no binding and overall straight and not warped.

If your knowledgeable about these carbs you can interchange parts. eg the throttle plate from one and the fuel bowl from another and the air horn from yet another

I have a box full of old Rochester parts that I keep for those rainy days.

There really quite simple once you understand what the different parts do.

I have a beauty from a 305 and I am simply going to take the jets and metering rods from a crappy one on a 350 and put them in the good one from the 305.

Thing is to ensure that all 3 main body pieces are straight/flat, not warped.

Also ensure the butterfly shafts and plates are in good working order no slop or binding

Warped = Vacuum leak = non working fuel circuits

Slop = vacuum leak

Binding = throttle stuck wide open

Seal up those fuel well plugs by very carefully drilling out the aluminum ones and then tap and install 10-32 pipe plugs and 7/16 pipe plugs with epoxy weld on the threads.

The carb will always give you grief if you don't seal the fuel well plugs.

Go to your local fastener shop and they can hook you up with the plugs and taps, drill bits too probably.

Clean the throttle valve plate with carb cleaner only. Clean the fuel bowl and air horn with parts cleaner very well.

BLow all passages out with compressed air before and after fuel wells are tapped. I blew mine out 4 times during the rebuilding process.

There is more to it then that. best thing is to get a good book on them and watch some youtube vids and just find out everything you can about them. Also its a good idea to dissemble and reassemble a couple of absolute junkers before attempting to work on your good ones.

It took me a while to figure them out but once you do youll be glad you did.


Oh and if you find a really shiny one at the junk yard even if the fuel inlet is oriented different GRAB IT !

 

[flyboy1100]

Why? What's so special about the shiny ones?

Sent from my Nexus 7 using Tapatalk

 

[flyboy1100]

Figure out what years what is?

You know, if you're up for it - and the junkyards in your area have plenty of these trucks - you could probably pull all the components required to restore most of the emissions package.

By far, the most expensive components are the one's associated with the air injection system - and that's if you can even find them. So, since that part of the emissions package is not a factor, restoring the remainder would not be all that hard.

There is a really good chance that your ECU is still fully operational - those early engine control systems were fairly basic and the modules were simple. Other than a tendency to develop cracks in the solder joints of the PC board, they were dependable.

It can seem confusing but, keep in mind that the engine control and emissions packages are independent of each other and are operated by different means:

The engine control system is primarily electrical. It is a group of:

1. Sensors, actuators and electronics on the engine.
2. The ECU under the dash.
3. The wiring that links everything together.

On the other hand, the emissions control system is almost totally vacuum operated. The only electrically controlled components in the emissions system - that I can think of - are the air pump diverter valve solenoids and a vapor canister purge solenoid. The operation of everything else is by vacuum and these components are controlled by either the various TVS's or the ported connections on the carburetor.

Here is a picture showing the location of the most common engine components that were used on the 1986 C/K series:

You must be registered for see images attach

Your engine code is going to be an "L" . This can be confirmed by checking the 8th digit of your VIN.

There are two types of "L" engine codes Federal & California. Assuming you have a Federal package, the following devices were originally installed:

Engine V8-350
Application 4 Bbl. Exc. Calif.
Engine Code [1] L
Figure No. 119
Devices & Systems
AIR, BPEGR, CC, DEC-V, DV, DVDV, EEC, EFE, EFE/DS-TVS, EGR-BS, EGR-SOL, ESC, ESC-KS, OC, PCV, TAC, TCC



The component key:

EXPLANATION OF SYSTEMS AND DEVICES



ABA Air Bleed Actuator
ACC Auxiliary Charcoal Canister
ACS Air Control Valve
AIR Air Injection Reaction
AIR-DS Air Injection Reaction Divert Solenoid
AIR-MGMT Air Injection Reaction Management System
AIR-SVV Air Injection Reaction Switching Solenoid Valve
APS Absolute Pressure Sensor
ASV Absolute Pressure Sensor
A.T. Automatic Transmission
BARO Barometric Pressure Sensor
BPEGR Back Pressure Exhaust Gas Recirculation
BPS Barometric Pressure Sensor
BPT Back Pressure Transducer
BVV Bowl Vent Valve
CAC Cold Advance Control
CC Charcoal Canister
CCV Canister Control Vent
CDR Crankcase Depression Regulator
CLFC Closed Loop Fuel Control
CP-TVS Canister Purge Thermal Vacuum Switch
CP-SOL Canister Purge Solenoid
CTS Coolant Temperature Sensor
C3 Computer Command Control
CV Crankcase Ventilation
DC Deceleration Control
DEC Diesel Electronic Control System
DEC-MCV Deceleration Mixture Control Valve
DEC-V Deceleration Valve
DPS Differential Pressure Sensor
DC/CP-TVS Distributor Spark & Canister Purge ThermalVacuum Switch
DS-DV Distributor Spark Delay Valve
DS/EGR-TVS Distributor Spark & Exhaust Gas Recirculation Thermal Vacuum Switch
DS/P-TVS Distributor Purge Thermal Vacuum Switch
DS/TCC-TVS Distributor Spark & Tramsmission ConverterClutch Thermal VacuumSwitch
DS-TVS Distributor Purge Thermal Vacuum Switch
DS-VCV Distributor Spark Vacuum Check Valve
DS-VR Distributor Spark Vacuum Regulator
DTVS Distributor Thermal Vacuum Switch
DV Diverter Valve
DVDV Distributor Vacuum Delay Valve
DVR-SOL Diverter Solenoid
EAC Electric Air Control Solenoid
EAC-V Electric Air Control Valve
EAC/EAS-V Electric Air Control & Electric Air Switching(Integral Type)
ED/ES-V Electric Diverter/Electric Air Switching Valve
EDV Electric Diverter Valve
EEC Evaporative Emission Control
EEC-PV Evaporative Emission Control Purge Valve
EEC-S Evaporative Emission Control Sensor
EEC-TVS Evaporative Emission Control Thermal Vacuum Switch
EFE Early Fuel Evaporation System
EFE/DS-TVS Early Fuel Evaporation & Diustributor Spark ThermalVacuum Switch
EFE-SOL Early Fuel Evaporation Solenoid
EFE/EGR-SOL Early Fuel Evaporation/Exhaust Gas Recirculation Solenoid
EFE-TVS Early Fuel Evaporation Thermal Vacuum Switch
EFE-VCV Early F uel Evaporation Vacuum Check Valve
EGR Exhaust Gas Recirculation
EGR-BPT Exhaust Gas Recirculation Back Pressure Transducer
EGR-BS Exhaust Gas Recircualtion Bleed Solenoid
EGR/CP-TVS Exhaust Gas Recircualtion & Canister Purge Thermal vacuum Switch
EGR/CP/DS-TVS Exhaust Gas Recirculation, Canister Purge &Distributor Spark Thermal Vacuum Switch
EGR/CP/TS-TVS Exhaust Gas Recirculation, Canister Purge &Trapped Spark Thermal Vacuum Switch
EGR/CP/TCC-TVS Exhaust Gas Recircualtion, Canister Purge &Torque Converter Clutch Thermal Switch
EGR/PWM-SOL Pulse Width Modulated Exhaust Gas Recirculation
EGR-S Exhaust Gas Recirculation Sensor
EGR-SOL Exhaust Gas Recirculation Solenoid
EGR-TDS Exhaust Gas Recirculaiton Temperature Diagnosis Switch
EGR-TVS Exhaust Recircualtion Thermal Vacuum Switch
EGR/TCC-TVS Exhaust Gas Recircualtion & Torque Converter ClutchThermal Vacuum Switch
EGR-VBS Exhaust Gas Circulation Vacuum Bleed Solenoid
EGR-VDS Exhaust Gas Recirculation Vacuum Diagnosis Switch
EGR-VRV Exhaust Gas Recircualtion Vacuum Regulator Valve
EGR-VS Exhaust Gas Recircualtion Vacuum Switch
EGR-VSV Exhaust Gas Recircualtion Vacuum Switching Valve
EPR Exhaust Pressure Regulator
EPR-SOL-EPR Solenoid
EPR Electric Purge Solenoid
EPR-SOL-EPR Solenoid
EPS Electric Purge Solenoid
ESC Electronic Spark Control System
ESC-KS Electronic Spark Control Knock Sensor
ESR Engine Speed Relay
ESS Engine Speed Sensor
EST Electronic Spark Timing
ETK Electronic Throttle Kicker
ETM Elapsed Timer Module
EVRV Electronic Vacuum Regulator Valve
FCS Fuel Control System
FIS Fast Idle Solenoid
FM Fuel Module
FVV Fuel Vapor Valve
HDE Heavy Duty Emission Calibration
HIC Hot Idle Compensator
IAC Idle Air Control
ISC Idle Speed control Motor
ISS Idle Stop Solenoid
LALS Lean Authority Limit Switch
LDE Light Duty Emission Calibration
MAIR Managed Air Injection Reaction
MAP Manifold Absolute Pressure Sensor
MAT Manifold Air Temperature Sensor
MCS Mixture Control System
MDE Medium Duty Emission Calibration
MDPS Manifold Depression Pressure Sensor
M.T. Manual Transmission
OC Oxidizing Catalyst
ORC Oxidation Reduction (3-Way) Catalyst
ORC/OC Oxidation Reduction & Oxidizing (3-Way &dual bed) Catalyst
OS Oxygen Sensor
PCS Purge Control Solenoid
PCV Positive Crankcase Ventilation
PWM-EGR Pulse Width Modulated Exhaust Gas Recirculation
P-TVS Purge Thermal Vacuum Switch
RVR Response Vacuum Reducer
SCS Slow Idle Fuel Cut Solenoid
SRDV Spark Retard Delay Valve
SSCS Stepped Speed Control Solenoid
SVB-TVS Secondary Vacuum Break Thermal Vacuum Switch
SVB/EGR-TVS Secondary Vacuum Break Exhaust GasRecirculation Thermal Vacuum Switch
TAC Thermostatic Air Cleaner
TBI Throttle Body Injection
TCC Tranwmission Torque Converter
TCC/EGR/CP/TS-VS Torque Converter Clutch, EGR, Canister Purge& Trapped Spark Thermal Switch
TCC-TVS Transmission Converter Clutch Thermal Vacuum Switch
TCC-VDV Transmission Converter Clutch Vacuum Delay Valve
TIVS Tip-In Vacuum Switch
TK Throttle Kicker
TPS Throttle Position Sensor
TRC Throttle Return Control
TVR Throttle Valve Relay
TVS Thermal Vacuum Switch
TVSS Trapped Vacuum Spark System
TVV Thermal Vacuum Valve
VB-TVS Vacuum Break Thermal Vacuum Switch
VCV Vacuum Control Valve
VDV Vacuum Delay Valve
VMV Vacuum Modulator Valve
VR Vacuum Regulator
VRV Vacuum Regulator Valve
VS Vacuum Sensor
VSS Vehicle Speed Sensor
VSV Vacuum Switching Valve

If you go through the list of what was on your truck (and eliminate all the emissions stuff) you have only about 5 components.

I don't know why that ISC actuator is not listed - it isnot on the Calif list either.

I have a Vin H, 305. I need to find out which years at not computer controlled. It would be nice to get my torque converter lockup to work though

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[chengny]

Oh yeah, your engine is a 305. Here is the component list for your application:

Engine V8-305
Application 4 Bbl., A/T Exc. Calif & High Alt.,Exc. Caballero & El Camino
Engine Code [1] H
Figure No. 117

Devices & Systems
AIR, BPEGR, CC, DEC-V, DS-DV, DV, EEC, EFE, EFE/DS-TVS, EGR-BS, EGR-SOL, EGR/CP/TCC-TVS, ESC, KS, OC, PCV, TAC, TCC, TIVS


If the ECU is good (and connected to the TCC) and there is signal from the speed sensor - it should just start working.

TCC diagnostic chart:

You must be registered for see images attach

Description and Operation


The ECM controls a solenoid mounted in the automatic transmission. When the vehicle reaches a specified speed, the ECM energizes the solenoid and the torque converter mechanically couples the engine to the transmission. When the brake is applied, or other conditions indicate that the transmission should operate as a normal fluid coupled transmission, the solenoid is de-energized.

 

[MadOgre]

The really shiny ones are remanufactured or new, although I don't know that there is such a thing as a brand new Rochester anymore.

Doesn't matter how well you clean your carb it will not be shiny new unless you have it refinished which usually is only the case with the remanufactured ones.

I don't believe the actual carb has anything to do with the lockup. So as long as you get one with electric choke you should be good as far as vacuum ports go. The older versions had less vacuum ports and in different places.

The electric choke versions were the most advanced featured ones until getting into the ECM controlled ones

I don't have to bother with smog crap up here so my setup is not emissions compliant LOL so I have no advice in that area.